One Difference Is All It Takes
by Creative Heart 1997
Summary: We've all read the stories, of a young wizard named Harry Potter. We've grown up or watched as our children grew up with stories of the Boy Who Lived. But what if something was different, what if he hadn't been alone at the Dursley's? What if Harry had a twin, a young girl named Katrina? How would things have been different? Well, you're about to find out. Rewrite in Progress!
1. The Twins Who Lived

Disclaimer: I do not own anything from Harry Potter- Nor am I making any profit from this.

Disclaimer/ AN: I use some parts of the first few chapters of the book very closely to the original to show the few small changes that occurred, this will change once I hit a part where things start to diverge more, although this may occur again later in the story for specific conversations I believe need to stay the same or very similar to the original. I have done almost word for the last paragraph of the first chapter of the first book because it is my favorite paragraph in the series and wanted to give it a spotlight here. All recognizable writing from the books comes from J.K. Rowling and is not my work.

AN: Hey guys, I'm sorry I'm starting something new rather than continuing my old stories, but I've had horrible writers block along with complete insanity in my life recently so I haven't been able to write. I've done this idea before… more than once, but I'm hoping to do it better this time, as I'm a lot older then I was and I know where I failed before. So on that note, I hope you all enjoy.

Summary:

We've all read the stories or seen the movies, of a young wizard named Harry Potter. We've grown up or watched as our children grew up with stories of the Boy Who Lived. But what if something was different, what if he hadn't been alone at the Dursley's? What if Harry had a twin, a young girl named Katrina? How would things have been different? Well, you're about to find out.

~Line Break~

July 31st, 1980- St Mungo's Hospital

Sirius Black sat in a row of chairs alongside his best friend Remus Lupin worry covering his features. Inside the room they could make out the sounds of Lily Potter screaming and cursing out her husband James. Peter Pettigrew rushed up juggling three mugs of coffee in his arms passing them around to the other two before taking a seat to wait with them. Hours passed the screaming dying down to the cries of a baby. The three men sighed in relief thinking it over before the screaming came again joining the wailing baby. Sirius stood up beginning to pace wanting to know what was going on. As the screaming died down again what sounded to be another baby's cry joined the first. The three friends waited with bated breaths as nurses came from the room followed by the doctor who gave them all a nod and grin before heading off. James Potter exited the room a while later a large goofy grin covering his face.

"It was Twins; The Doctor thinks the baby's heart beats must have matched perfectly for the muggles not have found the 2nd baby." He says excitedly to them. Sirius grins pulling James into a hug.

"Well Prongs when you do it, you really do it." Remus shakes his head at the bad joke his own grin not faltering. Peter squeaked in excitement.

"Come in you guys, and meet the newest two Potter's" James says ushering them all into the room, before rushing back to Lily who was lying tiredly in her bed holding two bundles of Blue and Pink.

"How are you Lill's?" Remus asks as he enters giving her a kind smile.

"As good as to be expected I suspect, I think I have Alice beat having had to deal with two deliveries even if hers took longer." She laughs jokingly smiling down at her two little miracles.

"Well what are their names, and who's older" Sirius presses coming over to peer at the two babies'.

"Well the oldest is our son Harry James Potter" James says motioning to the blue bundle.

"And then we have Katrina Lillian Potter, our little surprise" Lily says looking down at the bundle of Pink where a little baby stared up at her with wide eyes.

"Well we have the new Potter Prince and also a Princess" Sirius teases. James just grins at his friend.

"We wanted to ask you something Padfoot?" Sirius looks up curiously.

"We wanted to make you Godfather of the twins" Lily says smiling at him sweetly "We would have made you one as well if it where legal Remus." She explains. Remus just nods understandingly and grins at Sirius waiting for the reaction.

"You're serious?" He asks shocked he'd be trusted with something as important as this.

"No that would be you." James says snickering. Lily shaking her head in annoyance.

"Of course I'd love to be Godfather, now on that note can I hold my godchildren?" The others laugh at his puppy like excitement, each taking turns to hold the newest members of their little family.

~Line Break~

On October 31st, 1981, Lily and James Potter where murdered by Lord Voldemort. Their twin children one year olds Harry and Katrina Potter became legends to the wizarding world, the two having survived the Killing Curse, a curse no one had ever survived before. The only thing left to show this, was the matching lightning bolt scars on their foreheads, and the defeat of Lord Voldemort promptly ending the eleven year long war for the wizarding world. The twins where taken by a man named Rubeus Hagrid to Dumbledore who left them on the doorstep of their mothers sister and her husband along with a note explaining what happened.

~Line Break~

November 1st, 1981- Number 4 Privet Drive

A breeze ruffled the neat hedges of Privet Drive, which lay silent and tidy under the inky sky, the very last place you would expect astonishing things to happen. Harry Potter rolled over inside his blankets without waking up. One small hand reaching for his sisters beside him; Katrina Potter grasped her brothers hand her other closed on the letter between them. The twins slept on, not knowing they were special, not knowing they were famous, not knowing they would be woken in a few hours' time by Mrs. Dursley's scream as she opened the front door to put out the milk bottles, nor that they would spend the next few weeks being prodded and pinched by their cousin Dudley. . . . They couldn't know that at this very moment, people meeting in secret all over the country were holding up their glasses and saying in hushed voices: "To Harry and Katrina Potter – the twins who lived!"

~Line Break~

AN: Well that's it for Chapter one, I have Chapters 2 and 3, maybe even 4 written already. So I should be posting those in a few minutes. Hope you enjoyed! Please Review! (Please no Flames)


	2. The Snake from Brazil

Disclaimer: I do not own anything from Harry Potter- Nor am I making any profit from this.

Disclaimer/ AN: I use some parts of the first few chapters of the book very closely to the original to show the few small changes that occurred, this will change once I hit a part where things start to diverge more, although this may occur again later in the story for specific conversations I believe need to stay the same or very similar to the original. I have done almost word for the last paragraph of the first chapter of the first book because it is my favorite paragraph in the series and wanted to give it a spotlight here. All recognizable writing from the books comes from J.K. Rowling and is not my work.

AN: Well here's Chapter 2, I hope you enjoy!

Summary:

We've all read the stories or seen the movies, of a young wizard named Harry Potter. We've grown up or watched as our children grew up with stories of the Boy Who Lived. But what if something was different, what if he hadn't been alone at the Dursley's? What if Harry had a twin, a young girl named Katrina? How would things have been different? Well, you're about to find out.

~Line Break~

June 23rd, 1991- Number 4 Privet Drive

"Up! Get up! Now!"

Katrina woke with a start as her brother elbowed her jumping at their aunts rapping on their door.

"Up!" she screeched. They heard her walk away to the kitchen. Katrina rolled her eyes looking at Harry who looked back.

"You have the dream of the motorcycle too?" He asked quietly squinting to see her. She nods reaching out to grab both their glasses, Handing Harry his round ones and her putting on her own thick rectangular 'Nerd' glasses as Dudley called them.

"Are you up yet?" Aunt Petunia was back to get them.

"Nearly" said Harry, Katrina sitting up bowing her head.

"Well, get a move on you two, I want you to look after the bacon and sausage. And don't you dare let it burn, I want everything perfect on Duddy's birthday." Harry groaned, Katrina whacking him for it, knowing their aunt would be pissed.

"What did you say?" their aunt snapped through the door.

"Nothing, nothing..." Harry sits up pulling socks out from under the double cot him and his sister shared, pulling a spider off one and flicking it at his sister with a smile. Katrina whacked him upside the head. The two were used to spiders, because the cupboard under the stairs was full of them, and that was where they slept.

The two dressed and climbed out of the cupboard quickly going to the kitchen to watch the food. The two eat breakfast quickly knowing their cousin had a tendency to flip tables when upset. Katrina zoned out through her cousins rant about the number of present he had gotten being less than the year before, having finished her food already. Snapping out of it and sending a glare as Dudley's best friend Piers Polkiss arrived for their trip to the zoo, she was not happy with having to accompany them to the zoo even though she wanted to see the animals.

After a chaotic car ride in which Harry had nearly caused them to crash by stupidly mentioning him and his sister's shared dream to Uncle Vernon, they finally arrived at the zoo, going in the twins where each bought lemon Ice Pops when the ice-cream woman had asked what they wanted before the Dursleys could rush them away after having gotten Dudley and Piers ice cream.

"That Gorilla looks like Dudley" Harry whispered to his sister as they watched while licking their ice pops.

"Yeah, cept it isn't blonde" Katrina giggled, quickly falling silent when her uncle sent her a look.

The two even got to split a Knickerbocker glory when Dudley didn't want his first one because according to him it didn't have enough ice-cream when they had lunch. It was going very well the Twins keeping a bit away from the others so they could talk and avoid getting hurt by Dudley or Piers. But as was fate the good day did not last.

After lunch they went to reptile house. Dudley wasted no time in finding the largest snake there.

"It's big enough to wrap around uncle Vernon's car… at least twice" Harry whispered in awe.

"And maybe even around Uncle Vernon once" Katrina snickered back looking over the giant sleeping snake. Uncle Vernon was tapping the glass trying to get the snake to move for Dudley, when that didn't work Dudley shuffled away in boredom to see the other creatures. Katrina and Harry moved closer to the tank, Katrina reading the sign while Harry stood lost in thought. Katrina looked up startled when the snake moved having opened its eyes it had raised its head up to be at eye level with her and Harry when it… _winked?_ Katrina gasped eyes widening before grinning at Harry. The two of them winked back.

The snake jerked its head toward Uncle Vernon and Dudley, and then raised its eyes to the ceiling. As if to say plainly:

 _"I get that all the time."_

"I know," Harry murmured though the glass unsure if the snake could hear him. "It must be really annoying."

The snake nodded vigorously.

"Where do you come from, anyway?" Harry asked.

"The sign says Brazil, and that he was bred in the zoo." Katrina supplies the snake nodding along to her words.

"Oh so you've never actually been there?" The snake shook its head almost sadly, a deafening shout behind the twins making the three jump.

"DUDLEY! MR. DURSLEY! COME AND LOOK AT THIS SHAKE! YOU WON'T _BELIEVE_ WHAT IT'S DOING!"

Dudley came waddling over to them as quickly as he could.

"Out of the way, you two," he said punching both Harry and Katrina in the ribs sending the two to the hard concrete floor. What happened next would confuse everyone for weeks to come; no one saw exactly what happened. One second Piers and Dudley were leaning real close to the glass the next they were jumping back with howls of horror.

Harry sat up with a gasp; the glass of the boa constrictor's tank had vanished. The great snake was uncoiling itself rapidly, slithering out onto the floor. People throughout the reptile house screamed and started running for the exits. Katrina sat up beside her brother eyes wide as she pushed her glasses up her nose grabbing her brother hand in fear and shock.

As the snake slid past them the twins could have sworn they heard a hissing voice say "Brazil, here I come…. Thanksss, amigos."

The keeper of the reptile house was shocked.

"But the glass," he kept repeating, "Where did the glass go?"

After almost an hour of the Zoo director apologizing to Aunt Petunia and Uncle Vernon and Dudley and Piers telling anyone who would listen the story, which got more insane with each telling; they were finally on their way back home in the car. Where Piers just had to open his big mouth. "Katrina and Harry where talking to it, weren't you?"

Uncle Vernon waited until Piers was safely headed home before turning on the twins. He was so angry he could hardly speak. He managed through his own seething breathes to say, "Go – cupboard – stay – no meals," before collapsing into a chair where Aunt Petunia gave him a large brandy.

Katrina and Harry lay on their cot in their dark cupboard hours later, unsure if the Dursleys had yet gone to sleep. They could not sneak to the kitchen for food until they knew for sure or risk more yelling… or worse.

They had lived with the Dursleys for ten years, ten years of misery. Ten years of being treated as basic slaves. They had lived there since their parents had died in a car crash, or so their aunt had said. Neither of them could remember the night in which they had died, although both could recall if they truly tried a blinding flash of green light and a burning pain in their foreheads, they guessed it was the crash. The Burning pain had to have been when they got their matching lightning bolt scars. Katrina had spent a lot of time in the school library trying to figure out where the green light had come from, never finding anything. Neither had any recollection of their parents, they didn't even know their names for sure; let alone being sure of what they looked like. When they were young Katrina had asked her aunt if she looked like her mother, she had scoffed but had agreed that besides the black uncontrollable hair she was the spitting image of her, from the shape of her face to the color of her emerald green eyes. She had managed to get that Harry was the same, but for their father, other than his eyes and nose which matched his twins. They assumed they got their black hair from him. Petunia had admitted once that their mothers name of Lily and she had red hair, when she had scoffed at a women in a shop muttering about how she had the same unruly red hair of her late sister Lily. This brought them to believe that their fathers name was James seeing as Lillian was Katrina's middle name and Harry's was James, it was the only logical conclusion the two eight year olds could make.

When they were young the two used to spend hours coming up with crazy stories of some unknown relative coming and whisking them away from the pain and horror they faced every day. Although this never happened the two did seem to run into people that seemed to know them, strange people who would bow to them in shops or shake their hands then rush away or seem to almost disappear, they never did figure out why, having never gotten a chance to ask any of the strangers.

At school the two only had each other as the other kids where either to terrified of Dudley and his gang to befriend them, or thought they were weird in their large baggy hand me down clothing of Dudley's and broken glasses. Even the teachers barely spoke with them, thinking them dumb from their poor grades although they were very much the opposite, in fact they would be top of the class if they did not hold themselves back having learned early on if they did better than Dudley there would be consequences.

~Line Break~

AN: Well that's chapter 2, I hope you enjoyed, see you next time. Please Favorite, Follow, and Review if you did!


	3. Letters Recieved

Disclaimer: I do not own anything from Harry Potter- Nor am I making any profit from this.

Disclaimer/ AN: I use some parts of the first few chapters of the book very closely to the original to show the few small changes that occurred, this will change once I hit a part where things start to diverge more, although this may occur again later in the story for specific conversations I believe need to stay the same or very similar to the original. I have done almost word for the last paragraph of the first chapter of the first book because it is my favorite paragraph in the series and wanted to give it a spotlight here. All recognizable writing from the books comes from J.K. Rowling and is not my work.

AN: Well here's chapter 3, hope you enjoy!

Summary:

We've all read the stories or seen the movies, of a young wizard named Harry Potter. We've grown up or watched as our children grew up with stories of the Boy Who Lived. But what if something was different, what if he hadn't been alone at the Dursley's? What if Harry had a twin, a young girl named Katrina? How would things have been different? Well, you're about to find out.

~Line Break~

July, 1991- Number 4 Privet Drive

After weeks of punishment the twins had finally been allowed out around the start of the school holidays. The two were happy because the next school year they would no longer be going to school with Dudley, who was going to a boarding school, called Smelting's, where Uncle Vernon had attended secondary school. Harry and Katrina however would be going to the local public school, Stonewall High. Which Dudley found hilarious.

"They stuff people's heads down the toilet the first day at Stonewall," he told them grinning one day. "Want to come upstairs and practice?"

"No, Thanks" said Harry. "The poor toilet's never had anything as horrible as your head down it – it might be sick." Then the twins ran laughing, before Dudley could work out what he'd said.

One day in July as the family sat eating breakfast the mail came.

"Get the mail, Dudley," said Uncle Vernon from behind his paper.

"Make Harry get it."

"Get the mail, Harry."

"Make Dudley get it."

"I'll get it," Katrina says quickly standing up to rescue her brother from trouble. Uncle Vernon nods to her as she goes.

Four things lay on the doormat: a postcard from Uncle Vernon's sister Marge, who was vacationing on the Isle of Wight, a brown envelope that looked like a bill, and – _a letter for Harry, and another for Katrina._

Katrina picked them up and stared at them, her heart pounding as she looked at them. No one in their whole lives had written to them. There was no one too, no friends, family, not even clubs, or libraries. Yet here they were plain as day, addressed so obviously in emerald-green ink, on thick, heavy yellowish parchment without a stamp, that there was no mistake:

Mr. H. Potter

The Cupboard under the stairs

4 Privet Drive

Little Whinging

Surrey

Miss. K. Potter

The Cupboard under the stairs

4 Privet Drive

Little Whinging

Surrey

Katrina turned the envelopes over hands shaking in excitement, finding a purple wax seal bearing a coat of arms: a lion, an eagle, a badger, and a snake surrounding a large letter _H._

"Hurry up, girl!" Uncle Vernon shouted from the kitchen. "What are you doing, checking for letter bombs?" He chuckled at his own joke. Katrina quickly stuffed her and Harry's letters in her pocket before coming back in handing the others over to Uncle Vernon.

"Of course that's exactly what I was doing, I would never want you to end up blown up Uncle Vernon" She says sarcastically taking her seat. Harry covered his mouth trying not to laugh at her mouthing off. Uncle Vernon turned red in anger.

"Don't you dare speak that way to me girl, or you'll not like the consequences." He growled glaring. Katrina rolled her eyes before nodding annoyed.

"Harry and I our done, may we please be excused Aunt Petunia?" She asks not caring about the rest of her food, Harry giving her a questioning look before stuffing what was left of his food in his mouth. Petunia looked at them suspiciously before nodding.

"Fine but stay in the back garden or go to Mrs. Figg's, Dudley and I are going to the movies." She says pointedly. Katrina jumps up grabbing water bottles from the fridge for her and Harry before rushing out side dragging him along.

"Thanks Aunt Petunia, have fun at the movies" she called over her shoulder. Petunia, Vernon, and Dudley watched a bit shocked but let it go as them being weird.

"Kat, what's going on?" Harry asked once they got outside. Katrina pulling him far from the back door and behind the shed before she plopped down in the grass pulling the letters out of her pocket.

"Shh, keep it down Harry. These came for us today… I didn't want Uncle Vernon or Aunt Petunia to see… I don't trust they wouldn't have taken them away or something." She explains handing him his. "So let's open them together okay?" Harry looks at his letter then at her shocked before nodding slowly, a grin splitting his face.

"Alright on three?" He asks excitedly, Katrina nods.

"One…" Katrina starts

"Two…"

"Three!" the chorus together pulling open the seal and pulling the letters out opening them.

"Read them out loud together, okay?" Katrina asks stopping him from reading. Harry nods.

"Dear Mr. / Miss. Potter, We are pleased to inform you that you have been accepted at Hogwarts School of Witchcraft and Wizardry. Please find enclosed a list of all necessary books and equipment. Term begins on September 1st. We await your owl by no later than July 31st. Yours sincerely, Minerva McGonagall, Deputy Headmistress…" they read in sync. Katrina looks up shocked at her brother, before jumping as an owl lands on the top of the shed hooting down at them, before flapping down next to them, and holding out its leg where a piece of string is tied, for tying letters for delivery she guessed.

"Harry do you think this is real… that we… that we're… magic?" she asks looking between the owl and her brother.

"No it has to be a joke… I'm not a wizard… I'm… I'm just Harry…" he shakes his head in denial.

"But what about all the strange things we've done?"

"I… I don't know… I guess… I mean… there really is an owl… Maybe we should ask Aunt Petunia?"

"No! She'd never tell us the truth, she hates anything that's even slightly odd… in fact maybe that's why she hates us… we should respond, and send it with the owl… if its real we can ask them to send someone to prove it." She says standing up. Harry nods reaching out to hesitantly pet the owl, who lets him nipping at his fingers softly. "I'm getting paper and a pen wait here…" she rushes into the house to their cupboard, past a confused Petunia and Dudley, Vernon having left for work. She rushes back out with her and Harry's school bags "Sorry we wanted to draw and practice our math." She calls to her aunt on her way past.

Petunia narrows her eyes at that then sighs "So much like Lily those two" she mutters before locking the back door and leading Dudley out the front.

Katrina sits down beside Harry and the Owl pulling out some notebook paper, she hands it to Harry "Make an Envelope out of it while I start writing the letter." She instructs. Harry doing as she says rolling his eyes at her bossiness.

"She's always Bossy when excited." He tells the owl as he makes the envelope his sister sending him a small glare, to which he just gives a goofy grin. After a bought an hour, half way through of which Harry started helping, they finally finish the letter folding it into their home made envelope and writing Professor Minerva McGonagall on the front, before tying it to the owl's leg.

"Take this to Professor Minerva McGonagall, okay?" Katrina asks the owl who hoots at her as if to confirm before taking flight. The twins watch it leave before hiding their letters in their school begs and heading to Mrs. Figg's house until their Aunt returned home, Katrina enjoying playing with the cats.

~Line Break~

AN: Well that was chapter 3, hope you enjoyed! Please Favorite, Follow, and Review if you did!


	4. Magic Discovered

Disclaimer: I do not own anything from Harry Potter- Nor am I making any profit from this.

Disclaimer/ AN: I use some parts of the first few chapters of the book very closely to the original to show the few small changes that occurred, this will change once I hit a part where things start to diverge more, although this may occur again later in the story for specific conversations I believe need to stay the same or very similar to the original. I have done almost word for the last paragraph of the first chapter of the first book because it is my favorite paragraph in the series and wanted to give it a spotlight here. All recognizable writing from the books comes from J.K. Rowling and is not my work.

AN: Here's Chapter 4, sorry for the long wait!

Summary:

We've all read the stories or seen the movies, of a young wizard named Harry Potter. We've grown up or watched as our children grew up with stories of the Boy Who Lived. But what if something was different, what if he hadn't been alone at the Dursley's? What if Harry had a twin, a young girl named Katrina? How would things have been different? Well, you're about to find out.

~Line Break~

July 1991- Hogwarts

Minerva had just sat down at the small table in the great hall Albus Dumbledore, The headmaster, had them use during school holidays, between Albus, and Severus Snape, the potions master. When an owl flew in and landed beside her holding out its leg where a letter that seemed to be made out of Muggle notebook paper was tied. She untied the letter, letting the owl have some food before it flew off to the owlery. She looked at the homemade envelope in interest.

"What is it Minerva?" Poppy Pomfrey, the school mediwitch, asks from across the round table.

"It's a letter that seems to be made entirely out of muggle notebook paper; hmm I'm guessing one of the muggleborn first years must have sent it." She says looking it over. She opens it carefully as to not rip the thin paper inside. She unfolds it reading it a look of shock covering her face.

"What's wrong Minerva?" Severus as from beside her raising an eyebrow. She shakes her head.

"It's not from a muggleborn; it's from the Potter twins… Asking if their acceptance letters where some kind of joke… it seems their relatives told them Magic doesn't exist." She explains. The other three at the table, only the four of them having spent the summer at the school, look at her worriedly.

"Read the full letter to us Minerva." Albus suggests. She nods

"Dear Professor Minerva McGonagall, this is Katrina Potter (And Harry Potter, I'm just the one writing.) We received acceptance letters from you for Hogwarts School of Witchcraft and Wizardry; we have always been told magic isn't real, so I suspect you understand why these letters would confuse us greatly. If by some unbelievable chance this is real, could you please send someone from the school to explain to us and our relatives? We have not shown or spoken of our letters to our Aunt and Uncle, we're not sure if they knew about this or not and we'd rather not risk them telling us we can't go if it is real until we've spoken to someone from the school. Thank you for your help if this really does reach you (I mean we tied it to an owl, we're not entirely sure if that was just us being stupid or not…). We appreciate any help and information you could give us. Sincerely, Katrina Potter and Harry Potter." She reads out pausing every so often at miss spelled words.

"So Petunia didn't tell them about magic then?" Severus says raising an eyebrow although not sounding to surprised, having known Petunia when they were children.

"Minerva would you mind going to the Dursley's residence and informing them, as you do for most Muggleborn students? It may be best to treat them as such for the time being?" Albus asked.

"I'll go now, its suppertime so we should catch them all at home" Minerva tells them standing up. She leaves the great hall heading to the nearest fireplace connected to the floo network to floo to Arabella Figg's house.

~Line Break~

July 1991- Number 4 Privet Drive

The twins sat at the dinner table two days after they had received their letters, both completely convinced they were magic now, after Katrina had made a cat float after it had started to fall off Mrs. Figg's roof.

The family where just finishing supper when a knock is herd on the door. "I'll get it" Katrina offers standing from the table. She moves to the door opening it. "Can I help you?" She asks looking the strange women up and down. She was an older women wearing emerald-green… _robes?_

"Hello are you Miss. Potter?" She asks kindly. Katrina nods slowly. "I am Professor McGonagall; I received you and your brother's letter. Are your Aunt and Uncle home? We have much to discuss I believe." Katrina stares at her wide eyed before mutely nodding and letting her in, leading her into the kitchen.

"Aunt Petunia, Uncle Vernon, a professor from… Hogwarts is here to speak to us about Harry and me attending in September" She says catching her brother's eye nervously. Harry immediately stands up going to stand beside his sister. Vernon's eyes widen as he looks at his wife. Petunia chocks on her tea sputtering for a few moment before standing up.

"Katrina you know not to let a stranger in the house without our permission." She says pointedly while walking over to them. Vernon stands anger slowly making its way onto his features he turns to Dudley.

"Go up to your room Dudley and stay there." He orders. Dudley looks between the five of them but does as he is told mainly because of how angry his father looks.

"Mr. and Mrs. Dursley, I am Professor McGonagall; I'm the Deputy Headmistress of Hogwarts School for Witchcraft and Wizardry. I believe we met when your sister attended the school Mrs. Dursley." She introduces herself looking between the two.

"Of course, I remember you, why don't we move this to the sitting room." Petunia suggests giving the twins a look that could kill. The five of them move into the sitting room Petunia and Vernon sitting on the love seat the twins staying standing, and McGonagall taking a seat in an armchair.

"I'm here because the Twins here sent me a letter questioning the arrival of their Hogwarts letters, I take it you have never informed them of the Wizarding World?" She asks calmly.

"No we have not, and we wanted to keep it that way. The twins will not be attending Hogwarts." Petunia says sternly. Katrina gives her a glare but says nothing, knowing speaking up would make things worse on her and Harry. Harry just glares at the floor.

"Why is that, may I ask?" McGonagall asks raising an eyebrow "They are magical, young wizards and witches must be trained."

"We swore when we took them in we'd put a stop to that rubbish," Uncle Vernon spoke up, "swore we'd stamp it out of them! Wizard and Witch indeed!"

"So you did know!" Katrina yells angrily at Vernon and Petunia, no longer able to hold it back.

"You _knew_ we were – we're a witch and wizard?" Harry asks in anger as well.

"Knew!" shrieked Aunt Petunia suddenly. " _Knew!_ Of course we knew! How could you not be, my dratted sister being what she was? Oh, she got a letter just like yours and disappeared off to that – that _school_ – and came home every vacation with her pockets full of frog spawn, turning teacups into rats. I was the only one who saw her for what she was – a freak! But for my mother and father, oh no, it was Lily this and Lily that, they were proud of having a witch in the family!"

She stopped to draw a deep breath and then went ranting on. It seemed she had been waiting to say this for years.

"Then she met that Potter at school and they left and got married and had you two, and of course I knew you'd be just the same, just as strange, just as – as – _abnormal_ – and then, if you please, she went and got herself blown up and we got landed with you!"

The twins had gone white staring at her. "Blown up? You told us they died in a car crash!" They both yelled at the same time.

McGonagall is watching this with a raised eyebrow. "It seems you all have a lot to discuss, but I must make myself clear, the twins will be attending Hogwarts, their names have been down since the day they were born. They must be taught to control their magic." She says sternly to the Dursleys.

Vernon sneers at her "I will not pay to have some pot crack old fools teach them magic tricks." McGonagall's eyes narrow at that comment but she keeps an otherwise calm composure.

"You will not need to; they each have a trust vault with money their parents left them for Hogwarts." She explains.

"Then why have we not seen any of the money while having to raise them!" Vernon shouts face pure red in anger.

"The money is only available for use by the twins come their eleventh birthdays, and is to be used for their schooling and personal use, it is not meant for you nor will you being getting any of it." The professor explains, calmly waiting for the Dursleys to cool off. Vernon finally realizing he's lost shuts up letting Petunia handle it.

"If we have no choice in them going then so be it, but we will not be going anywhere near your world, so you will have to find someone else to take them school shopping." Petunia finally decides. "And I ask you keep your kind out of our home unless completely necessary, we want our son exposed to this as little as possible." McGonagall nods.

"Of course, either I or one of my colleagues can come by on the 31st; to take the two school shopping; if that's alright? I understand if you have other plans as that is the twins Birthday." She suggests.

"It's perfect, I'm sure they'll enjoy seeing he magical world on their birthday, we can always celebrate with them when they get home." Petunia says lying through her teeth. The twins both knowing no celebration was happening.

"I suggest you inform the twins of what the letter Professor Dumbledore left you said, before the 31st then." McGonagall presses standing up. "You have much to explain to them Mrs. Dursley, I expect you shall?" Petunia nods.

"Of course, they will be informed before the 31st," Petunia agrees. She proceeds to walk the professor to the door. Once she was gone she returns to the room. "Alright Vernon we need to move them into a room with real beds, before they return. Why don't you go buy two twin sized beds, while I tell them what they need to know?" She suggests to her husband. Vernon nods still furious looking. Vernon retrieves Dudley and goes to buy the beds and Mattresses and other things needed for the room, also informing Dudley as to what is going on.

"Alright then, Your mother was a witch," Petunia begins explaining, starting with the accidental magic her sister performed in her youth, to the day the twins arrived on the door step. She even gave them the letter Dumbledore wrote her. The Twins listened shocked then read the letter over and over again, shocked to learn of their fame, and to find out their parents, and now they were so much more than they had ever imagined.

~Line Break~

AN: Well that was chapter 4, hope you enjoyed! Please Favorite, Follow, and Review if you did!


	5. Into Magic

Disclaimer: I do not own anything from Harry Potter- Nor am I making any profit from this.

Disclaimer/ AN: I use some parts of the first few chapters of the book very closely to the original to show the few small changes that occurred, this will change once I hit a part where things start to diverge more, although this may occur again later in the story for specific conversations I believe need to stay the same or very similar to the original. I have done almost word for the last paragraph of the first chapter of the first book because it is my favorite paragraph in the series and wanted to give it a spotlight here. All recognizable writing from the books comes from J.K. Rowling and is not my work.

AN: Here's Chapter 5, sorry for the long wait!

Summary:

We've all read the stories or seen the movies, of a young wizard named Harry Potter. We've grown up or watched as our children grew up with stories of the Boy Who Lived. But what if something was different, what if he hadn't been alone at the Dursley's? What if Harry had a twin, a young girl named Katrina? How would things have been different? Well, you're about to find out.

~Line Break~

July 31st, 1991- Number 4 Privet Drive

The twins had been living in what used to be Dudley's 2nd bedroom for around a week now; it was cramped but not nearly as cramped as the cupboard. The biggest change was the fact they had real beds, and how they no longer shared a bed. At first neither could sleep without the other but after the full week it was getting easier. Katrina had hung drawings she had made on the wall to make the room feel more like their own and they had created a calendar out of notebook paper counting down the days to their eleventh birthday, and the day they go to Hogwarts. Another large change was Aunt Petunia had taken them shopping for new clothing, neither had ever been and they had had immense fun picking out the clothing. She had also taken them to get new glasses, with new prescriptions; neither of them had ever been able to see so clearly. They quickly realized why they were suddenly being treated so well, it was because the Dursleys where afraid of the professors at Hogwarts hurting them, for mistreating the two. Neither twin was stupid enough to complain or point this out to their relatives, just happy to have things of their own finally.

On the day of their birthday the twins where up early waiting for whomever was taking them shopping for school. When a large knock was herd on the front door both twins raced form their seats at the breakfast table to get the door. Harry being faster than his sister got there first pulling the door open then freezing staring up at the gigantic man standing on the porch.

"Ello, you must be Harry, My names Rubeus Hagrid Keeper of Keys and Grounds at Hogwarts." He introduces himself. Petunia follows the twins over, looking the man up and down.

"Make sure they are home before supper" Petunia tells him before ushering the twins out the door and closing it. The three depart, Hagrid answering many questions about where they are going, a place called Diagon Alley.

~Line Break~

"First place to go is Gringotts." Hagrid says as they leave the Leaky Cauldron out into the magnificent Alley, away from the fans inside, and the strange Professor Quirrell. The two nod Hagrid having told them it was the bank on their way there, along with his wish for a Dragon, which Katrina can't say she wouldn't mind having one as well, much to the annoyance of her brother. As they passed the insane shops and the many Witches and Wizards, Katrina couldn't help but imagine what it would have been like to grow up around this, rather than with the Dursleys. Her hatred for Voldemort growing as she thinks of what could have been.

 _Enter, stranger, but take heed  
Of what awaits the sin of greed,  
For those who take, but do not earn,  
Must pay most dearly in their turn.  
So if you seek beneath our floors  
A treasure that was never yours,  
Thief, you have been warned, beware  
Of finding more than treasure there._

"Like I said, yeh'd be mad to try an' rob it," said Hagrid. Katrina and Harry nod remembering the conversation on the way there.

"Well the poems cool," Katrina says with a smile reading it, "If they make things like it, I think I'll like Goblins." Harry rolls his eyes at her.

The three enter the bank, after Hagrid taking forever to find their vault keys the three head to Harry's vault first, Katrina's being right next his. They fill up on money for both of them before Katrina decides to ask something that was bothering her. "Um Mr. Griphook sir?" The goblin looks at her shocked at the attempted show of respect from a Witch, as most Wizards and Witches treated them horribly. "Is there any form of card, like a muggle debit card, that we could use in shops so as to not have to drag around giant bags of money, or maybe a magic bag that we can use, that would withdraw money from our account without having to make so many trips?"

"Yes there are bags that many wizards use similar to that, if you wish we could set up bags like that for you two when we are done down here?" Katrina nods with a smile.

"Yes please, sir." Harry smiles at his sister not sure why he didn't think of that.

After getting something from a vault for Dumbledore the three met with an account manager and set up the bags for the two. They also set up a day in August for the twins to return and be informed of all Potter accounts they have at Gringotts, including hearing their parents will, which they decided they should see if Aunt Petunia wanted to come with them for.

After they had finished at Gringotts the three continued their shopping, slowly checking off their lists until all they had left was their wands. Hagrid leaves them at Ollivander's wand shop while he runs an errand. The two entered looking around, jumping as an old man with creepy moon like wide eyes appeared.

"H – Hello?" Katrina says startled.

"Ah yes," said the man. "Yes, yes. I thought I'd be seeing you soon. Harry and Katrina Potter." It wasn't a question. "You both have your mother's eyes. It seems only yesterday she was in here herself, buying her first wand. Ten and a quarter inches long, swishy, made of willow. Nice wand for charm work. Your father, on the other hand, favored a mahogany wand. Eleven inches. Pliable. A little more power and excellent for transfiguration. Well, I say your father favored it – it's really the wand that chooses the wizard, of course." He moves closer to them reaching out with his hands to touch both twins' scars. "And that's where… I'm sorry to say I sold the wand that did it," he said softly "Thirteen-and-a-half inches. Yew. Powerful wand, very powerful, and in the wrong hands… well, if I'd known what that wand was going out into the world to do…" He shook his head then started measuring Harry deciding to start with the oldest.

Katrina snickered as he measured between Harry's nostrils much to Harry's confusion. Then sighed when he began measuring her before looking for their wands. "Twins wands tend to be very similar, made from cores from the same creature, or the same wood." He pulls out wands two at a time having them try them. After more than 50 wands each Ollivander finally stops a thoughtful look on his face.

"Tricky customers, eh? Not to worry, we'll find the perfect match here somewhere – I wonder, now – yes, why not – unusual combination – holly and phoenix feather, one eleven inches, the other ten inches, nice and supple. The feathers come from the same phoenix and the wood the same tree." Harry took the eleven inch wand, Katrina taking the ten inch wand. Harry felt a sudden warmth in his fingers. He raised the wand above his head, brought it swishing down though the dusty air and a stream of red and gold sparks shot out the end like a firework, throwing dancing spots of light on to the walls. Katrina brings hers up with a grin, bringing hers down as well, rainbow sparks flew from the end of the wand twirling in spirals, dancing around them. Harry and Katrina grin at each other excitedly as Ollivander cried,

"Oh bravo! Yes, indeed, oh, very good. Well, well, well… how curious… how very curious…" He took the two wands returning the, to their boxes and wrapping them in brown paper, still muttering to himself, "Curious… curious…"

"Sorry, but _what's_ curious?" asked Harry.

"I remember every wand I've ever sold, Mr. Potter. Every single wand. It so happens the phoenix whose tail feathers reside in your wands, gave another feather – just one other. It is very curious indeed that you two would be destined for these wands when their brother – why, their brother gave you those scars."

Katrina gasped, looking uneasy.

"Yes, thirteen-and-a-half. Yew. Curious indeed how these things happen. The wand chooses the wizard, remember… I think we must expect great things from you two, Mr. and Miss. Potter… After all, He-Who-Must-Not-Be-Named did great things – terrible, yes, but great."

Harry shivered, not sure if he liked Mr. Ollivander much. They paid the 7 Galleons each for their wands and hurried out of the creepy little shop. As they walk out they ran into Hagrid standing there holding an owl cage with a beautiful snowy owl inside, and a wicker cat carrier, the front rungs making an adorable black kitten inside viewable.

"Happy Birthday, Harry, Katrina!" He grins at them handing the owl cage to harry and the wicker basket to Katrina.

"Hagrid, you didn't need to get us anything." Katrina says shocked looking at the kitten, a large smile on her face.

"Don' mention it," said Hagrid gruffly. "Don' expect you've had a lotta presents from them Dursleys." The twins nod looking at their pets happily. "I even got you the stuff you'll need."

After the best day they'd ever had the twins return home bringing everything up to their room, where they stayed playing with their new pets until dinner. No celebrations where had not even a wish of happy birthday, but that was okay, because they had each other, and a new friend in Hagrid. Later that month the twins would return to Gringotts and finally hear their parents will, then off to Hogwarts.

~Line Break~

AN: Well that was chapter 5, hope you enjoyed! Please Favorite, Follow, and Review if you did!


	6. Truth Exposed

Disclaimer: I do not own anything from Harry Potter- Nor am I making any profit from this.

Disclaimer/ AN: I use some parts of the first few chapters of the book very closely to the original to show the few small changes that occurred, this will change once I hit a part where things start to diverge more, although this may occur again later in the story for specific conversations I believe need to stay the same or very similar to the original. I have done almost word for the last paragraph of the first chapter of the first book because it is my favorite paragraph in the series and wanted to give it a spotlight here. All recognizable writing from the books comes from J.K. Rowling and is not my work.

AN: Here's Chapter 6, sorry for the long wait!

Summary:

We've all read the stories or seen the movies, of a young wizard named Harry Potter. We've grown up or watched as our children grew up with stories of the Boy Who Lived. But what if something was different, what if he hadn't been alone at the Dursley's? What if Harry had a twin, a young girl named Katrina? How would things have been different? Well, you're about to find out.

~Line Break~

August 15th, 1991- Gringotts Bank, Diagon Alley

The twins walked into the bank shocked to see Professor McGonagall standing there along with Hagrid, and four men and three women. They walk over.

"Professor what are you doing here?" Katrina asks politely.

"We were informed of your parents will being read, we're on the list of people they left to hear it." She explains, "These are Professor Dumbledore, headmaster of Hogwarts, Professor Flitwick, head of Ravenclaw house and he'll be your charms professor, Professor Snape, he's head of Slytherin House, and potions master and professor at Hogwarts, Madam Pomfrey, Mediwitch at Hogwarts, Professor Sprout, head of Hufflepuff house, and she'll be your Herbology professor, Andromeda Tonks, she was a friend of your parents, and finally Remus Lupin, he was one of your parents best friends. We're all that's left of the very large list of people they left." The twins nod shaking hands with everyone politely.

"Well it's nice to meet you all, we thought we'd be stuck hearing it on our own." Katrina says smiling shakily at them all. Harry takes his sisters hand, nodding to all of them.

"Petunia isn't coming?" Snape asks raising an eyebrow.

"She didn't want too, She really – dislikes the wizarding world, and she said to tell her if anything had been left for her." Harry explains looking uncomfortable.

Before anyone can respond Griphook comes over "We're ready for you all now." He shows them to a large room with a large table a Goblin named Ragnok sitting at the head. Name cards had been placed around the table to show them where to sit. The twins sitting to the right of Ragnok, Dumbledore to the left; the professors placed down the left side beside the headmaster, Remus and Andromeda beside the twins.

"We have been called here today to read the last will and testament of Lord James Potter and Lily Potter nee Evans. This reading is very late in coming." He points out looking at the adults in the room, all of whom look a bit guilty for never thinking of it. "I shall now read the will…"

"We James and Lily Potter being of sound mind, body, and magic give to you our final will and testament. First we would like to state that Peter Pettigrew was our Secret Keeper, so if we are killed by Lord Voldemort or his death eaters, it is Pettigrew who betrayed us not Sirius Black. " Gasps of shock fill the room, Harry and Katrina who had done extensive research on their family and their parent's death looking just as confused as everyone else.

"To Sirius Black, the best friend I (James) have ever had, my brother, we leave to you our greatest joys, our children Harry James Potter and Katrina Lillian Potter. We know you will take good care of them as their godfather with the help of Remus, and their godmother Alice Longbottom. I (Lily) would like to add under no circumstances are my children to be left with my sister Petunia Dursley. To Remus Lupin, our closest friend and allie, we leave the sum of 5 million Galleons, and the cottage in New Forest where the basement has been set up for your furry little problem. We want you to use this money to create a better life for yourself. We are so sorry for ever doubting you and leaving you out of the loop of who our real secret keeper was, Peter had us all fooled. Please keep an eye on Sirius and make sure he raises the twin's right, as you are and always will be their unofficial godfather." Remus closes his eyes trying not to break down crying. Katrina who is sitting between him and Harry places a gentle hand on his arm in comfort. Remus looks at it giving her a weak smile, mouthing 'Thank You' to her.

"To Peter Pettigrew, we leave nothing, but hopefully a cell in Azkaban where you can rot for all eternity you lying bastard." Looks of guilt fill the faces of everyone in the room. "To Severus Snape we leave an apology, I (James) would like to tell you how truly sorry I am for what my friends and I did to you in school, we were bullies and we were wrong. I hope you can find it in your heart to one day forgive me. We also leave forgiveness, Sev I (Lily) forgive you for what you said and did, I was hoping I would get the chance to reconcile with you but if your hearing this that didn't happen. I hope you the best and ask you put aside your feelings towards Sirius and help him raise my babies, help them grow to be as great of people as I know you will one day become." Snape looks like he's going to be ill but keeps his face down. "To Albus Dumbledore, we leave our thanks, you did all you could to protect us and we are grateful for that, but we ask you leave our children out of your plans for the 'Greater Good', they do not need to help in this horrible war, they just need to be loved and taken care of." Dumbledore nods a look of guilt covering his old features. "To Professor Minerva McGonagall (Minnie)," McGonagall and Remus chuckle at the old joke. "we leave the sum of 10 thousands Galleons, as a thanks for everything you did for us while we were in school." McGonagall lets a tear fall, smiling at this sadly.

"To the other professor's (Filius Flitwick, Pomona Sprout, and Poppy Pomfrey) we invited here today we leave the sum of 5 thousand Galleons each as thanks for the help you have given us over the years." The three look a bit shocked but happy. "To Rubeus Hagrid we leave the sum of 20 thousand Galleons for being our friend, we hope you have a wonderful life and help make our children's lives at Hogwarts as fun as you have ours." Hagrid lets out a large sob sounding like a wounded dog. Dumbledore and McGonagall pat his shoulder trying to calm him down.

"To Alice and Frank Longbottom, we leave the partial custody of our children Harry James Potter and Katrina Lillian Potter, help Sirius make them great. Alice you are my (Lily) greatest friend, please look after my children as if they were your own. To Andromeda Tonks we leave the sum of 10 thousand Galleons, as thanks for the support you have given us and Sirius throughout the years." Andromeda nods sadly.

"Finally, to our beautiful children Harry and Katrina Potter, we leave everything else, to be shared between the two of you. Harry upon your 17th Birthday you will become Lord Potter, head of the family. Katrina although Harry will be head of the family we are leaving you with as many rights to the Potter Fortune and vaults as him. Our amazing little prince, and our beautiful little surprise, we love you both so much. Daddy loves you, Mama loves you. Please look after one another, we wish you both the happiest and brightest of lives. Love James Potter, and Lily Potter. Witnessed by Sirius Orion Black on August 31st, 1981." Katrina starts crying part way through hiding her face in her brothers shoulder, Harry just stares at Ragnok, tears streaming down his face.

Dumbledore stands up, "I believe I need to go speak with Amelia Bones about the innocence of Mr. Black if you would all excuse me." He takes his leave the others watching him go.

"Mr. and Miss. Potter the two of you shall receive the rest of your inherence other than your trust vaults upon your 17th birthdays." Ragnok informs them. "All who are to receive money or properties, if you would please follow Griphook, he shall help you." The large number of people follow behind Griphook out of the room, the others slowly taking their leaves after giving Harry and Katrina their apologies.

The twins leave the bank sadly, but also with new hope in their hearts, their aunt and uncle where never supposed to have had custody of them, meaning according to Ragnok they could petition the Ministry of Magic to transfer their custody to their godfather, they just had to wait until he was free.

~Line Break~

August 17th, 1991- Azkaban Prison

Sirius Black sat in his cell, having transformed back to human from his animagus form when he heard voices coming. He looks up as his cell door is opened, Amelia Bones and a few Aurors standing before him. The guards move forward pulling him up and out. They walk through the prison until they reach a room in which a simple boot sits.

"Take a hold of the boot, Black" one of the guard's orders as the others all take hold, the guards holding the boot with one hand, the other holding Sirius. Sirius, greatly confused, does as he is told. The Portkey activates and they are spun away.

When the spinning stops it is clear they are in St. Mungo's Hospital, Sirius is brought to a room and told to get in the bed, where he is cuffed to the bed by one hand. The guards leave, Amelia takes a seat in a chair beside the bed.

"Black you have been brought here to recover for two months' time, at which point you will be given a trial to check your innocence. You will be placed under veritaserum." She explains.

"But, why now?" Sirius asks his voice cracking from lack of use.

"Two days ago, Harry and Katrina Potter called a meeting at Gringotts to read the final will and testament of James and Lily Potter, which was never read as I'm sure you had realized considering you know what it said." He nods shocked.

"But – the twins – are only – eleven right? Why would they think to – to have it read?"

"The Potters account manager suggested it to them while they were school shopping, upon their first visit to Gringotts. After the reading Albus Dumbledore came straight to me to petition for your freedom, stating we had made a grave error." Sirius nods still in shock. "I will see you in two months, Mr. Black." Amelia gives him a nod before leaving.

Sirius Black laid on the bed, for the first time in ten years he finally felt hope.

~Line Break~

AN: Well that was chapter 6, hope you enjoyed! Please Favorite, Follow, and Review if you did!


	7. Authors Note - Rewrite Information

I know I know it's been years since I updated so an author's note is not what you want. But there is good reason I'm going to be re-writing this story from the start to up the quality a bit, the first few chapters should be up in the next week or so, so keep an eye on my account if you're interested in reading it.

I'm sorry this has been left for so long but real life has been more than a little chaotic what with college and health and family issues that have been happening. I turn 21 this May and with the launch of the Harry Potter mobile game I wanted to work on a Harry Potter story, so I'm jumping back into this one.

Well that's it for now; I'll update this story with information when I post the rewrite.

~ Kat


	8. AN: Rewrite Posted

Hey Everyone! The rewrite is up!

s/12923796/1/One-Difference-Is-All-It-Takes-Rewrite

Not sure if the link will work so just copy and paste it or go to my page and you'll see the rewrite!


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